An internal combustion engine, such as a multi-cylinder diesel or gasoline engine, typically includes a cylinder block defining a plurality of cylinder bores, which reciprocally carry respective pistons therein. Each cylinder bore may include a cylinder liner in which the piston actually reciprocates. Cylinder liners allow a cylinder block with a particular cylinder bore configuration size to be used with multiple different diameter pistons by simply changing the cylinder liners for a particularly configured engine.
In the assembled engines, the liners may be held in place by a specific configuration of the liner and flange design. Generally constructed, liners have been supported at their upper ends in the cylinder block.
By using liners, they may be machined separately which permits accurate control of cylinder wall thickness and assures uniform cylinder cooling. Many diesel engines are designed and built with replaceable cylinders, and replacement cylinder and piston sets are manufactured and made available for overhauling diesel engines. The cylinder liners may be removed and replaced if worn through use over time. These liners are typically held in place by a flange between the block and cylinder head.
In some applications, the liner installation and assembly of the engine, and the operating conditions in the engine (especially the high temperatures involved with starting up and cooling off) may create undesired stress levels in the liners. One of the greatest risks to cylinder liners is a flange crack resulting in liner failures. The highest stresses generally occur at the location of an arcuate or radiused fillet at the juncture of the outer surface of the cylinder with the lower surface of the radial flange. The thickness of the cylinder wall may be further reduced by an undercut provided at and/or adjacent to the fillet to provide for machining of the outer surface of the cylinder wall with room for tool run-out adjacent to the fillet, again a possible stress/fracture point.
Over the years, engineers have devised a long list of ways to reuse cylinder liners. In fact, the reuse of cylinder liners dates far back, in conjunction with other engine components on and in machines and vehicles. From those early dates forward, numerous manufacturers of engine blocks have included some remanufacturing strategies to allow the reuse of components involved with the block. These strategies included recoating the liners, resurfacing the liners—outside and inside, and initiating new gaskets and rings for use with the replacement liner to ultimately provide strength of a potential area of structural weakness. However, heretofore, none have addressed the simultaneous issues of liner wear and structural damage due to flange stresses, which can lead to expensive consequential damage. One aspect of these types of restoration and remanufacturing operations is that each is very expensive and can often only be justified economically in commercial operations or in situations in which the cost of replacement of the entire engine is prohibitive.
The present disclosure is directed to overcoming one or more of the problems set forth above.